It is well-known that the key of industrialization of TD-SCDMA is terminal, while the bottleneck of terminal is the research for the terminal chip scheme. The chip design for the second generation mobile terminal is mostly prone to use solidified application-specific hardware circuits, while software is only used to implement a little part of chip design. It takes three to five years from an initial chip design to a commercial application of the chip, and the chip design using solidified application-specific hardware circuits is hard to meet the new changed requirements.
TD-SCDMA is one of the 3rd mobile communication system standards formally accepted by the International Telecommunication Union (ITU), new requirements are proposed to the mobile terminal based on the 3rd generation mobile communication technology, which are shown on the following aspects:
More plentiful applications; supporting multi-mode, saving user cost, having the capability of providing more flexible service, and being favorable to the carrier to use spectrum resources more reasonable; lower cost; providing customized services, and easily updating the system.
In order to meet new requirements and face new challenges, a more optimized system architecture must be adopted at the key technology step of the mobile terminal design, namely, the chip design, so that the chip design is suitable to more mobile terminals to decrease the cost of repeated design.
Until now, there is no commercialized application-specific baseband chip suitable to a multi-mode terminal including TD-SCDMA mode. The application-specific baseband chip performs the mode selection through a main control unit of the system, receives IQ data from Radio Frequency (RF), implements the baseband processing of the corresponding mode, and transmits data to be transmitted after the baseband processing by the system via an RF channel.